INTRODUCTORY. 73 



eleventh chapter of the first section of this work. In- 

 vestigations similar to those carried out or suggested by 

 Fechner and Wundt were stimulated by the appearance 

 of Helmholtz's two celebrated treatises on ' Physio- 

 logical Acoustics ' and ' Physiological Optics/ and by 

 the original philosophical interest associated with them 

 in the mind of their author, leading him to a serious 

 study of Kant's works. However different the pro- 

 gramme of Zeller might at the time have appeared 

 to be from that of Wundt, both had this in common, 

 that they practically abandoned the speculative line of 

 thought which in Germany had reigned supreme during 

 the first half of the century. Zeller himself was brought 

 up in the Hegelian School ; Wundt, on the other side, 

 connected for some time with Helmholtz in his academic 

 teaching, had been brought up in the school of Exact 

 Science. The hopelessness of the later developments of 

 the Hegelian School, which had split into two exactly 

 opposite factions, seemed to produce, on one point, the 

 same results in the mind of Zeller as did in the mind 

 of Wundt the hopefulness with which, in the School 

 of Johannes Miiller, Helmholtz and others approached 

 the borderland of physical and mental phenomena. The 

 common conviction arose that speculative philosophy, the 

 orthodox form of metaphysics, was played out. Both 

 Zeller, who was a leader in historical and critical studies, 

 and Wundt, who was equally so in physiological work, 

 emphasised those lines of study in which each of them 

 had attained his early successes, the one pointing to 

 criticism and history, the other to the exact methods of 

 research. The historical spirit in Hegel's school pre- 



